Abstract: A timing error correction technique for use in data communications receivers such as WLAN (Wireless Local Area Network) receivers is provided where an input signal is received that has a timing error, the timing error is corrected, and a signal having a corrected timing error is output. The timing error correction comprises performing an early-late correlation on the signal that has the corrected timing error. The early-late correlation comprises the generation of at least one early and late sample pair, the generation of an error signal that is indicative of the difference between the early and late samples, and the generation of at least one control signal based on the error signal. A time offset correction algorithm is performed dependent on the control signal.

Abstract: An improved decision feedback equalization technique is provided that may be used in data communications receivers such as those in WLAN (Wireless Local Area Network) systems. The decision feedback equalizer comprises a feedforward filter that is connected to receive an input data signal and output a filter representation thereof. The feedforward filter has a filter characteristic that depends on filter coefficient data. The decision feedback equalizer further comprises a filter coefficient computation unit for generating the filter coefficient data and outputting the generated data to the feedforward filter. At least one data processing circuit is provided that receives a mode switch signal for switching its operational mode. The data processing circuit is arranged for performing a feedforward filter function in one operational mode and a filter coefficient computation function in another operational mode.

Abstract: A WLAN (Wireless Local Area Network) receiver with a synchronization unit is provided, wherein the synchronization unit comprises a frequency error correction unit configured to perform a frequency error correction process, a phase error correction unit configured to perform a phase error correction process, a filter circuit capable of applying one of at least two different filter transfer functions, wherein a first one of said at least two different filter transfer functions is a frequency error correction filter transfer function for use in said frequency error correction process and a second one of said at least two different filter transfer functions is a phase error correction filter transfer function for use in said phase error correction process, and a controller unit connected to said filter circuit to select one of said at least two different filter transfer functions.

Abstract: A complementary code decoder technique is provided where the encoded input data is first parallelized. From the parallelized data, correlation values are generated by a correlator circuit that is capable of changing its correlation characteristics depending on at least one control signal. Different control signals are sequentially provided to the correlator circuit thereby driving the correlator circuit to sequentially generate multiple correlation values from the parallelized data, based on different correlation characteristics. From the multiple correlation values, the correlation value that represents the optimum correlation is identified. This technique significantly reduces the gate count of the decoder structure, thus saving chip area and manufacturing costs.

Abstract: An error correction technique for data communication receivers such as WLAN (Wireless Local Area Network) receivers is provided. The error correction technique is for correcting a frequency and/or phase error in an incoming digitally modulated signal. A constellation manipulator is provided that is adapted to manipulate the phase constellation system of the incoming digitally modulated system by mapping each constellation point of the phase constellation system to a predefined range of phase angles. The predefined range has a width of less than 2&pgr;. Further, an error detector is provided that is connected to receive data from the constellation manipulator. The data pertain to the manipulated phase constellation system. The error detector is adapted to evaluate the data to detect the frequency and/or phase error.

Abstract: An average tracking mechanism for a data communication receiver is provided. The average tracking mechanism of the receiver is connected to receive an input stream of data samples and is adapted to keep track of an average over a predefined number of most recently received data samples. The average tracking mechanism comprises a calculation unit that is adapted to calculate an approximate value of the average and a storage unit for storing calculated approximate values. The calculation unit is adapted to calculate the approximate value by retrieving a previously calculated approximate value from the storage unit and calculating a weighted sum of the retrieved approximate value and a current data sample. The average approximation technique may be used in a comb filter of a preamble detector in a WLAN receiver.

Abstract: A receiving unit in a communication system for receiving a communication signal. The receiving unit is preferably a wireless local area network (WLAN) receiver. The receiving unit comprises a synchronization data detection section and a frequency error correction section. The synchronization data detection section detects predefined synchronization data included in the received communication signal and computes an initial estimate of a frequency error of the received communication signal. The frequency error correction section corrects the frequency of the received communication signal based on frequency error estimates. An initial frequency error estimate used for a first frequency error correction is received from said synchronization data detection.

Abstract: A WLAN (Wireless Local Area Network) receiver is provided that provides at least two acquisition units and at least two tracking units. The acquisition units perform a synchronization acquisition process, and the tracking units perform a synchronization tracking process. The acquisition units are arranged for being operated sequentially while the tracking units are arranged for being operated simultaneously. In an embodiment, frequency and phase error correction may be performed separately, and those units that operate at higher sampling rates may be located before lower-rate units. The synchronization process may include data-aided as well as non data-aided algorithms.

Abstract: A wireless local area network receiver is provided that has an interference reduction unit for reducing interchip interference in a received signal that is modulated using a complementary code keying technique such as CCK-11. The interference reduction unit comprises a decision feedback equalizer that has a feedforward filter for reducing precursor interference and a feedback filter for reducing postcursor interference in the received signal. The receiver may perform channel estimation to optimize the filter coefficients during the preambles of the incoming sequence.